If this is real it's probably nothing more than an idea sheet. But other sites have said the japanese is broken and the source is known for fabricating leaks.
Smash Bros. has never been named after consoles, though. Eponymous, Melee, Brawl...Affray? Lol, I hope not.
tl;dr people can do more than one thing at once
My last post was bad. I never completely meant otherwise. We knows that it's at least in planning phase because he's openly discussed his ideas for Smash Bros Wii U and 3DS, and technical work has probably started to some degree if the engine is being worked on. I meant that the game probably hasn't started full development because he's still finishing up Icarus. What's more is that, as of e3, Sakurai is assembling a new team for Smash Bros. Wii U and 3DS, and he stated the only reason that they were announced so early was to attract the attention of prospective staff. For reference, the same thing happened in 2005 with Brawl.
I'm hoping Nintendo decides to hold another pre-e3 SpaceWorld, focused on Wii U, and that we'll have a teaser for this game (really unlikely :'( ).